1. Field of the Invention
The present invention relates to a yaw moment control apparatus for a vehicle which controls a yaw moment by producing a driving force in one of left and right wheels and a braking force in the other.
2. Description of the Related Art
A yaw moment control apparatus for a vehicle is known which has left and right follower wheels connected by a transmission provided with a pair of hydraulic clutches and produces a yaw moment in a leftward turning direction by engaging one of the hydraulic clutches to decrease the speed of the left wheel and to increase the speed of the right wheel or, alternatively, produces a yaw moment in a rightward turning direction by engaging the other of the hydraulic clutches to decrease the speed of the right wheel and to increase the speed of the left wheel. In Japanese Patent Application Serial No. 8-324323, the present assignee has previously proposed another yaw moment control apparatus for a vehicle in which a left hydraulic pump connected to and rotated by a left wheel and a right hydraulic pump connected to and rotated by a right wheel are connected via a hydraulic circuit, and either one of a driving force and a braking force is produced by the left hydraulic pump and the other by the right hydraulic pump, thereby controlling a yaw moment.
However, it is also possible to control the yaw moment of a vehicle by varying cornering forces of wheels, instead of by controlling the distribution of a driving force and a braking force between a left wheel and a right wheel.
The present invention has been made in view of the above-described problem, and the object of the present invention is to make further improvements to the art disclosed in Japanese Patent Application No. 8-324323 so that the control of a yaw moment of a vehicle can be more accurate by varying cornering forces of wheels.